The present invention relates to hardware for securing backplanes to a frame module, and more particularly to a support bracket that provides structural support for areas of a backplane having large cutouts.
Backplane circuit boards need to be attached to a frame module in such a way so as to withstand the perpendicular forces applied to the backplane when circuit cards are inserted from the front of the module, and when cables are installed and removed from the back of the module. Securing the backplane to a frame module is typically done by attaching the backplane along the top and bottom edges and across the board center to extrusion module support cross-members by a number of screws. To accommodate pass-through cable connectors that are normally mounted very close to the board edge and would interfere with the support cross-members, standoffs are used between the backplane and the support cross-members. The attachment screws go through the standoffs and serve to hold the standoffs in place. The number and placement of connections attaching the backplane to the support cross-members is governed by the minimum number of connections structurally required by the backplane, and space available on the backplane board.
As the density of components on backplanes increases, there is a problem in locating enough positions on the backplane for support connections. This is a particular problem where a bank of pass-through cable connectors requires a large cutout, and the closely packed cable connectors do not allow room for support connections along the backplane edge. This leaves a relatively long narrow strip at the edge of the backplane board structurally unsupported that is vulnerable to fatigue, cracking and breaking with repeated insertion and removal of cables from the cable connectors, and that also allows the backplane board to deflect when printed circuit cards are inserted, possibly resulting in the circuit card not being properly seated.
Accordingly, it is an object of the present invention to provide a backplane support bracket that will provide structural support to the backplane along the backplane edge strip of the cutout for a bank of cable connectors without requiring access to the backplane edge strip between the cable connectors.
The invention of Applicants is a backplane support bracket comprising a flange with opposing engaging tabs extending downward, and a flange extension arm, extending from the flange generally in the direction joining the two opposing engaging tabs, with a connecting tab also extending downward. The opposing engaging tabs and flange fit over the module support cross-member in close fit, and the connecting tab is secured to one of the cable connectors of the bank using a cable connector mounting screw located along the backplane edge strip of the cutout. With one or more backplane support brackets so installed, the bracket greatly reduces flexing of the cutout edge strip when cables are inserted and removed from the cable connector bank and when circuit cards are inserted and removed from the board.